Core forming mechanism



March 13, 1934. P, H. ROMPH CORE FORMING MECHANISM Filed Sept. 10, 1931 A Fa UL HHUMFH? Patented Mar. 13, 1934 I I 1,950,632 ooim FORMING MECHANISM Paul H. Romph, Detroit, Mich., assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application September 10, 1931, SeriaI No. 562,057

.6 Claims. (01. 22-40) This invention relates to the method of and provide a core forming machine with improved mechanism for forming sand coresa means for exhausting air and excess sand from Core forming machines, in which the sand is the core box. blown into the molds by air under pressure, are Another object of this invention is to prousually provided with an air chamber and a vide a core forming machine with a core box 0 movable sand transfer member which carries having a single opening therein to receive sand the sand from'the supply hopper to position in under air pressure and means adjacent the core alignment with and, between the air chamber box opening and associated therewith through and the core box or mold. From the sand which air and excess sand which may be forced transfer member the sand is blown into the core into the core box after the core is completely 5 box and packed therein by the air and sand formed and solidly packed, may be exhausted. under pressure. Another object of the invention is to provide In machines of this character it has been the movable sand transfer member of a core the practice to form the core boxes or molds blowing machine with improved means for conwith an inlet opening and with separate holes ducting the air and excess sand from the core 7.

or apertures through the wallsthereof to perbox. i mit the escape of air as the sand is deposited A further object of the invention is to proin the mold to form the core. Usually these vide an improved method of forming sand cores outlet openings are formed in the side walls wherebythe sand and. air are blown into the near the bottom of the core .box. core box and exhausted therefrom in substan- 75 This method of exhausting the air has been tially the same plane through a single opening found to be quite unsatisfactory due to the fact in the core box. v that when the core-is completed and taken from Other objects and advantages of the inventhe mold, the sand around each of these holes tion will appear from the following description is found to be loose and not well packed. This taken in connection with the accompanying o undesirable condition is brought about by some single sheet of drawing which forms a part of of the sand being blown out of the holes with this specification, and in which: I the air during the core filling operation leaving Fig. 1 is a side view of the core blowing masmall depressions in the core around each hole. chine incorporating this invention, shown partly The result is rough, loosely packed and uneven in elevation and partly in section. 5 cores. Referring to the drawing it will be seen that By the present invention these and other unthe machine comprises a base 10 supporting a desirable features in machines of this characpair of vertical columrisll, only one of which is ter are overcome. shown. Attached to the base and the forward The invention contemplates the provision of edge of the vertical column is a pneumatic cyla core box having a single opening therein and inder l2 and operating therein is a piston 13 a face plate or cover associated with the openhaving a top or table 14 carrying a yoke 15 ing which is formed with openings or passagesecured thereto, as by bolts 16. The upper end ways through which the sand and air may be of the column is inclined forwardly and merges blown into the core box and through which the into'a hollow blowing head 17 which is positioned 5 excess sand and air may be exhausted in subdirectly above the center of the table 14. stantially the same plane in which they enter. A sand hopper 18 is mounted on the support- Provision is also made for conducting the sand ing column to the rear of the blowing head and and air from the core box opening to a posihas its discharge opening 19 at the same level tion outside the machine. -By such construction as the mouth 20 of a sand transfer member 21. 109 it is possible to exhaust the entire charge of The hopper 18 'is adapted tocontain asuitable sand from the transfer member into the mold. core sand, preferably a bond sand, and may be The continued pounding of the sand under provided with any convenient form of agitator pressure upon the sand already in the mold (not shown) to insure the steady flow of sand results in the sand comprising the core being from the hopper when desired. packed to a greater extent than has heretofore The. sand conveyer or transfer member 21 is been possible and the excess sand which is not in the form of a hollow elliptical cylinder and is required to form a well packed core will be movable from a position beneath the hopper blown out the top of thecore box. mouth to a position beneath the blowing head.

55 It is an object of the present invention to For this purpose the transfer member 21 is supof the frame 22 is extended as at 30 to form a closure slide for the discharge opening 19 of the hopper 18 when the conveyer is moved away.

In its forward position the sand transfer member is directly over the open mouth of a collapsi-- ble core box form 31 which is adapted to be received between the arms 32 and. 33 of the yoke 15. The core box may be of. any desired con-- struction and usually includes a bottom plate 34 resting on the bottom of the yoke and suitable end plates and side plates 35 and 36. The interior configuration of the box to formthe desired core shape may be effected by properly shaping the inner walls of the bottom, end. and side plates. The plates conveniently fit together with the ends between the sides, and are held together by means of dowel pins or are merely provided with engaging tongues and groovesso that they can be quickly assembled. and then disassembled as the core is formed so that it can be removed intact. It may be here noted that the only opening provided in the walls of the core box is the large opening in the top thereof. through which the sand is received.

With the corebox parts in position on the yoke and with the piston 13 lowered and the sand transfer member beneath the hopper, sand. may be delivered into the transfer member by gravity until it is full. Air is then admitted to the head end of the cylinder 26 and the transfer member is. moved to a position between and in alignment with the blower head 17 and the core box, at which time the slide 30 will close the bottom of the hopper. Air is then admitted to the interior of cylinder 12 through a conduit 37 which may be connected to the main air control valve (not shown).

When air under pressure is admitted to the cylinder 12, the piston 13 is moved'upwardly carrying the yoke and core box with it. This causes the upper edges of the core box sides and ends to register with a face plate or cover member 38 which is secured to theperipheral flange 39 of the sand transfer member. This plate or cover member 38 forms a closure for both the lower end of the sand transfer member and the opening in the core box. The cover has an opening 40 therein which communicates with the interior of the sand transfer member and through which the sand is blown into the core box. This opening is of such size that the nor-- mal consistency of the sand prevents it from falling therethrough by gravity.

As the piston- 13 is raised, the core box is car-- ried upwardly to engage a gasket 42 which may be secured to the under side of the face plate 38. The gasket 42 forms an air-tight seal between the core box and the face plate 38 of the sand receptacle when the core box is moved into position to receive sand. and air. When the piston and core box are thus raised, the whole sand transfer member is slightly elevated due to the looseness of the rollers 23 on their ways,

so that the upper end of the sand transfer mem- I ber which already registers with the opening in.

the blowing head is caused to tightly engage it and form an air-tight Joint with the assistance of a gasket 43. if desired. The blowing head may beprovided with a suitable perforated baffle plate 44- and an air inlet conduit 45 so that air can be blown atgreat pressure and properly distributed over the. surface of the sand in the sand. transfer member to blow it into the core boxl Under the high pressure of the air the sand. is blown through the opening 40 in the face plate 38- and packed solidly in the mold or core box. 31.

Owing to the high pressure of air needed to properly deposit the sand. in the core box, it is necessary that means he provided for clamping the sections of the box together. For this purpose one arm 33 of the yoke 15 may be provided with a face which is inclined in the opposite direction from the side of the core box. A wedge 53 is provided having the proper inclination to fit between the inclined surface of the yoke arm 33 and the side of the core box so that when the wedge is tightly pressed in place, the core box is securely clamped between it and the opposite arm of theyoke. The wedge has mounted on it a pair of rods, only one of. which 54. is shown, which slide in holes provided in an extended portion 41 of the flange 39 on the bottom of the sand transfer member. The rods are provided on their upper ends with stop nut sv 55 to engage with the upper surface of the flange as the yoke, is lowered and to assist in withdrawing the wedge. Mounted on the rods between. the under surface of the flange portions 41 and the upper face of the wedge are strong coil springs 56. which are instrumental in forcing the wedge into position as the yoke is elevated to bring the upper edges of the core box into engagement with the gasket 42 and the face plate 38 on the sand transfer member.

In order that the air may escape from the core box as the sand. is deposited therein, and the excess sand which. is fed from the sand transfermember after the core box is completely filled and packed may be exhausted, a second passageway 47 is provided in the face plate or cover member 38. The passageway, as shown, is formed in a manner to connect. the interior of the core box at the upper end thereof with the atmosphere through. the plate 38 when the core box is in operative position. This opening 47 is. formed in the cover plate 38 in substantially the same plane as the opening 40 therein so that the air and sand may both enter and be exhausted from the core box without any air passing through the sand forming the body of the core.

Suitably secured as by a nut 48 to the face plate 38 in registry with the exterior port of the passageway or opening 47 is a short length of conduit 50. As shown, this conduit is adapted totelescopically engage another length of conduit 51. The conduit 51 may extend from the machine to any convenient point of deposit. As

shown in the drawing, the pipe extends down theside of the support 11, issecured thereto by a bracket 52 and terminates near the floor or other convenient location at which the excess sand is to be deposited. In some instances it may be convenient to extend the conduit 51 to aconveyer which is sometimes employed to supply'the hopper 18 with sand.

It will be understodthat suitable valves are provided to admit. air tothe respective ends of the cylinder 26, to the main cylinder 12 and to the blower head 17. The vertical movement of the yoke and core box may be arranged so that the core box is lowered to such a position that it may be conveniently slid onto conveyers and the core and box rolled away for treatment or use.

It will be apparent from the foregoing that simple and efficient means have been provided whereby the sand which is to fill the core box may be packed to a greater extent than has heretofore been possible and whereby a smooth core of uniform contour may be produced. By the present invention it is possible to completely empty the sand transfer member 21 so that the maximum amount of sand is forced into the core box, where in machines previously employed the point at which the core box was completely filled and well packed with sand was more or less a matter of conjecture on the part of the operator. By providing a sand transfer member of a predetermined capacity that is large enough to contain more than enough sand to fill the core box when solidly packed, it is possible to. accurately fill and pack the core box uniformly on each operation of the machine. This result is obtained due to the fact that the sand is forced under pressure into the core box until, and even after, the core box is completely filled and packed. Heretofore this has been impossible.

It will also be apparent that the invention, as shown and described, is susceptible of numerous modifications in design without departing from the spirit thereof. For example, the core box itself might be provided with an auxiliary opening adjacent the top thereof similar to that shown in the face plate 38 which could be adapted to exhaust'the excess sand and air therethrough. Other changes and modifications will become apparent to those skilled in the art and, therefore, this invention is to be limited only by the scope of the appended claims.

What I claim is:

1. In a core forming machine having a core box with an opening in a wall thereof, a cover member associated with said opening having an inlet opening through which sand and air may be blown into the core box and an outlet opening through which air and excess sandmay be exhausted from the core box.

2. In a core forming machine having an air chamber connected to a source of air under.

pressure, a core box having a single opening at one end thereof, and a hollow sand receptacle adapted to be interposed between the air chamber and core box; a face plate associated with said sand receptacle adapted to register with the opening in the core box, said face plate having a passageway therein through which sand is blown from the receptacle into the core box and another passageway through which the excess sand and air are exhausted from the core box.

3. In a core forming machine having a core box, a blowing head and a sand transfer member movable into and out of alignment with the core box and the blowing head; a face plate associated with said member adapted to contact the core box, said face plate having a passageway therein through which sand may be blown from,

the transfer member into the core box and another passageway through which excess sand and air may be exhausted from the core box and a conduit connected to said face plate in communication with said exhaust passageway comprising telescoping members adapted to slide one within the other when the transfer member is moved out of alignment with the blower head and the core box.

4. In a core forming machine, a core box having a wall formed with a pair of openings therein communicating with the interior of the box and in close proximity to each other, one of said openings forming the sole inlet through which sand may be blown by compressed air and the other of said openings forming the sole outlet through which air and sand may be exhausted from the interior of the core box.

5. In a core forming machine, a core box having an open end, a face plate slidable across the open end of said box said face plate having an inlet opening therethrough and an outlet opening communicating with the interior of the box in a relation close to the inlet opening and extending laterally through the side of the face plate, and conduit means connected with the face plate in communication with the outlet opening.

6. In a core forming apparatus, the combination of a core box having a top wall with a pairof openings therethrough forming a single inlet and a single outlet for air and sand, means communicating with the inlet opening for blowing sand into the box, and means communicating with the outlet opening for conveying air and excess sand from the box. 

